Definition 1.1 (cf. [1]}) 
If \(A\)  is a subset of a finite group \(G\) , then the corresponding Cayley graph \(\operatorname{Cay}(G; A)\)  is the undirected graph whose vertices are the elements of \(G\) , and such that vertices \(g\)  and \(h\)  are adjacent if and only if \(g^{-1} h \in A \cup A^{-1}\) , where \(A^{-1} = \lbrace \, a^{-1} \mid a \in A\,\rbrace \) .

